activity
20242026
most cited: New insights from deep spectroscopic observations of the tidal tails of the globular clusters NGC 1261 and NGC 1904

11 citations · 23 across the 9 of their papers we have counts for

collaborators

10 papers

astro-ph.SR2026

AGB-star Mass Transfer Products in Stellar Streams as Tracers of Density in Dissolved Star Clusters

Newlin C. Weatherford, Madeleine McKenzie, Sam A. Usman

The least dense globular clusters (GCs) appear to host the highest fractions of stars with chemical signatures of mass transfer from asymptotic giant branch (AGB) companions. Recen…

astro-ph.SR2026

The -Process Alliance: Actinide Abundances, Variation, and Evolution in Metal-Poor Stars

Shivani P. Shah, Rana Ezzeddine, Erika M. Holmbeck +11

The actinides, including thorium (Th), are the heaviest observable elements synthesized in the universe, holding clues to the extremes of the astrophysical and nuclear conditions o…

astro-ph.SR2025

Detailed Chemical Abundance Analysis of the Brightest Stars in the Turranburra and Willka Yaku Stellar Streams

Kaitlin B. Webber, Terese T. Hansen, Jennifer L. Marshall +20

We present a detailed chemical abundance analysis of the three brightest known stars from each of the Turranburra and Willka Yaku stellar streams using high-resolution Magellan/MIK…

astro-ph.GA2025

Chemical Abundances in the Metal-Poor Globular Cluster ESO 280-SC06: A Formerly Massive, Tidally Disrupted Globular Cluster

Sam A. Usman, Alexander P. Ji, Jandrie Rodriguez +6

We present the first high-resolution abundance study of ESO 280-SC06, one of the least luminous and most metal-poor gravitationally bound Milky Way globular clusters. Using Magella…

astro-ph.GA2025★ 7 cited

Flipping of the tidal tails of the Ophiuchus stream due to the decelerating Galactic bar

Yong Yang, Geraint F. Lewis, Denis Erkal +16

The Ophiuchus stellar stream presents a puzzle due to its complicated morphology, with a substructure perpendicular to the main track (spur), a broadened tail (fanning), and a shor…

astro-ph.GA2024★ 11 cited

: New insights from deep spectroscopic observations of the tidal tails of the globular clusters NGC 1261 and NGC 1904

Petra Awad, Ting S. Li, Denis Erkal +22

As globular clusters (GCs) orbit the Milky Way, their stars are tidally stripped forming tidal tails that follow the orbit of the clusters around the Galaxy. The morphology of thes…

astro-ph.GA2024★ 3 cited

Chemical Abundances in the Leiptr Stellar Stream: A Disrupted Ultra-faint Dwarf Galaxy?

Kaia R. Atzberger, Sam A. Usman, Alexander P. Ji +11

Chemical abundances of stellar streams can be used to determine the nature of a stream's progenitor. Here we study the progenitor of the recently discovered Leiptr stellar stream,…

astro-ph.GA2024★ 2 cited

Inferring dark matter subhalo properties from simulated subhalo-stream encounters

Tariq Hilmi, Denis Erkal, Sergey E. Koposov +9

In the cold dark matter paradigm, our Galaxy is predicted to contain >10000 dark matter subhaloes in the range which should be completely devoid of stars. Stella…

astro-ph.SR2024

Spectacular nucleosynthesis from early massive stars

Alexander P. Ji, Sanjana Curtis, Nicholas Storm +39

Stars formed with initial mass over 50 Msun are very rare today, but they are thought to be more common in the early universe. The fates of those early, metal-poor, massive stars a…

astro-ph.GA2024

Multiple Populations and a CH Star Found in the 300S Globular Cluster Stellar Stream

Sam A. Usman, Alexander P. Ji, Ting S. Li +14

Milky Way globular clusters (GCs) display chemical enrichment in a phenomenon called multiple stellar populations (MSPs). While the enrichment mechanism is not fully understood, th…